Atomic Layer Deposition of Transition-Metal Dichalcogenides

Two-dimensional (2D) transition metal sulfides (TMDs) semiconductors, represented by MoS2, are regarded as promising candidates to advance Moore's law in the postsilicon semiconductor era, as they possess the advantages of high carrier mobility, high switching ratios, tunable bandgap, and atomic-level thickness, as well as combining with good mechanical properties. The exploration of high-quality large-area 2D materials is crucial for investigating new physical phenomena and further extending their applications in microelectronics and optoelectronics. Among the techniques for producing high-quality 2D materials, atomic layer deposition (ALD) stands out as a self-limiting surface chemical reaction-based method. It offers more advantages in terms of step coverage, wafer size uniformity, and controllable stoichiometric ratio, which is expected to overcome the bottleneck in the utilization of 2D materials in optoelectronic integrated devices and future large-scale applications. In this paper, we provide an overview of the structure and properties of TMDs, and then focus on the latest progress in the ALD-based preparation of TMD thin films. Key factors influencing the film quality are discussed, and we conclude by discussing the potential future development trends in this field.